The present invention relates to a skin evaluation method and a skin evaluation device. In particular, the present invention relates to a skin evaluation method and a skin evaluation device for evaluating skin conditions such as dullness and translucency.
In recent years, as awareness about beauty has been increasing, attention has been focused on various skin conditions such as dullness and translucency. In many cases, dullness is caused over the entire face, around eyes and a mouth, or the like. Dullness refers to, for instance, the decrease in brightness of skin, which makes the skin look dark, or the decrease in ruddy glow of skin, which makes the skin look yellowish.
As a method for measuring the dullness and translucency, there is a method of observing the surface of skin by using a colorimeter for measuring the brightness and color tone of the skin. However, dullness, decrease in translucency, and the like are caused by various factors such as aging, sunburn and saccharification of collagen inside skin, and are greatly affected not only by the conditions at the surface of the skin but also by the conditions at various sites in the skin from the epidermis to the dermis. Accordingly, when only a colorimeter is used for the measurement, the skin conditions cannot be accurately ascertained.
Furthermore, as a technique for analyzing the internal structure of skin, optical coherence tomography (OCT) is known. The optical coherence tomography is for analyzing skin from its surface to a depth of 1 to 2 mm in detail. For instance, in the method of analyzing epidermis proposed by JP 4790231 B, a profile of optical reflectance relative to the depth in skin is created, and the internal structure of the skin is analyzed based on the form of the profile to measure the thickness of the epidermis.